U.S. Kicking Russian Rocket Engines to the Curb
United Launch Alliance photo
After relying on Russian-made rocket engines for national security launches since the early 2000s, the United States is preparing to blast off with next-generation engines made within its borders.
United Launch Alliance — a joint venture between Lockheed Martin and Boeing — and Elon Musk’s SpaceX are gearing up for the first batch of national security launches awarded to the companies in 2020. More than 30 launches will be carried out between ULA’s Vulcan Centaur and SpaceX’s Falcon 9 and Falcon Heavy from fiscal year 2022 through 2027 as part of phase 2 of the National Security Space Launch program, or NSSL.
The upcoming launches will allow the United States to phase out the Russian-made RD-180 — the first-stage engine used to power ULA’s Atlas V rocket.
The RD-180 engine is a dual-combustion chamber, dual-nozzle engine designed and built by the Russian company Energomash. The engine burns a mix of kerosene and liquid oxygen fuel to give it enough thrust for the initial boost phase of flight, said Chris Stone, senior fellow for space studies at the Mitchell Institute for Aerospace Studies.
Using the RD-180, the Atlas V rocket has carried out dozens of launches to deploy U.S. national security spacecraft — including military, spy and GPS satellites — as well as commercial launches. The Atlas V was the preferred vehicle for the Defense Department for nearly two decades, along with ULA’s Delta IV family of rockets.
Both rockets gave the United States “assured access to space,” a policy that ensures the capabilities necessary to launch and insert U.S. national security payloads into orbit, said ULA President and CEO Tory Bruno.
“We were set up originally to have two redundant systems at least for the government, because we were the only domestic launch company,” Bruno said in an interview with National Defense. “What if your pad fails, or there’s a flaw in one of the rockets? You always have to have two ways.”
Despite the Atlas V’s near perfect launch rate, Russia’s 2014 invasion of Ukraine and annexation of Crimea sparked calls from U.S. lawmakers to cut off the reliance on the RD-180 by making a new engine for the Atlas V on U.S. soil — a task easier said than done, Stone said.
“The idea was, ‘Let’s just design a new engine to stick in the back end of an Atlas V,’ and that’s not how it works,” Stone said. “It’s not like an airplane where you can slide out an engine and slide in a new one. You basically build the engine and design everything around it.”
Furthermore, the RD-180 has a design that U.S. rocket engine makers were unable to replicate, he added. This includes a unique metal mixture for the walls of its combustion chamber that keeps it from cracking during the pressure of the launch, he said.
Realizing the demand for new launch vehicles and engines, the Space and Missile Systems Center with the National Reconnaissance Office released a request for proposals in 2019 seeking two domestic launch service contracts as part of the new National Security Space Launch program, according to a Congressional Research Service report titled, “Defense Primer: National Security Space Launch.”
One year later, ULA and SpaceX were announced as the winners of the two contracts, beating out Northrop Grumman and Blue Origin, the report said. ULA will cover 60 percent of the missions contracted by Space Systems Command, while SpaceX will take the rest.
The decision to develop a new rocket and engine has been reaffirmed since Russia’s full-scale invasion of Ukraine in February, when Moscow formally announced it would cease all sales and support of the RD-180 to the United States in response to sanctions placed on the country.
“We were able to say, ‘So what? We don’t need your stinking engines anymore,’” Stone said.
While phasing out its remaining Atlas V rockets and RD-180s already purchased, ULA will be using its new Vulcan Centaur heavy-lift launch vehicle for its upcoming assignments. The rocket has been under development since 2014, and shifting the company’s focus from two rockets to one has allowed it to keep costs low, Bruno said.
The Vulcan has the same single-core structure of the Atlas V with the ability to add up to six solid rocket boosters, but is built much larger so that it has more lift capacity than a Delta IV, he said. Solid rocket boosters are used to provide thrust from initial takeoff through the first ascent.
“The fact it is a single-core heavy [rocket] makes that heavy mission — that today is only flown by Delta IV Heavy — really inexpensive. It’s about a third, even closer to a quarter of the cost,” Bruno said. The Delta IV Heavy is the most powerful rocket in ULA’s fleet, and has carried a number of large National Reconnaissance Office payloads into orbit.
The Vulcan’s first-stage liftoff will be powered by a pair of Blue Origin-built BE-4 engines. ULA partnered with Blue Origin in 2014 to jointly fund the development of the engine, which will also be used in Blue Origin’s New Glenn rocket the company submitted for the phase 2 competition.
As the rocket booster’s main engine, it uses liquid methane for fuel — another departure from the kerosene-powered RD-180, Bruno noted.
But before the Vulcan can begin launching national security payloads, it must complete two successful commercial missions to receive certification — a process that has been pushed back due to BE-4 engine delays.
Bruno said some delays were expected, given both the smaller staff size of Blue Origin when ULA first decided to use the BE-4 and the complicated process it takes to build a rocket engine from scratch.
ULA has worked closely with Blue Origin while also rearranging the Vulcan’s development to accommodate the BE-4, he said.
“Things we might have done one step after the other … we do that in parallel,” he explained. “You might take a little bit of extra risk on our development side in case we would have to go backwards and change something because the engine turned out a little differently, but that’s a manageable risk.”
The first two BE-4 flight engines are nearly finished. Once completed, they will undergo certification testing, he said. From what he has seen so far in the BE-4’s performance configurations, Bruno said he is “very happy with the engine.”
The Vulcan will be moving right into its certification launches, bypassing any test flights, he noted. The rocket’s maiden flight will carry Astrobotic Technology’s Peregrine lunar lander payload for NASA’s Commercial Lunar Payload Services program and is currently on track to launch “by the end of this year,” he said.
In May, Space Systems Command assigned ULA and the Vulcan its first five national security missions as part of National Security Space Launch phase 2. While no specific timeline for the launches was announced, they are expected to occur over the next two years, according to a Space Systems Command news release.
SpaceX received three missions from Space Systems Command as its first part of the contract. The company plans to use its Falcon 9 and Falcon Heavy rockets, both of which are powered by the company’s own Merlin family of kerosene and liquid oxygen engines during the first stage of launch.
One of the reasons the Falcon family stands out is the ability for SpaceX to recover the first stage of the rocket — including the Merlin engines — for reuse, Stone noted. RD-180 engines are not able to be used in a second launch, he added.
SpaceX did not respond to National Defense’s requests for an interview.
Although missions contracted under phase 2 of the National Security Space Launch program have not yet begun, both the Space Force and space industry are already looking toward the next phase of medium- and heavy-launch contracts.
The biggest change in the launch industry is how the Space Force is responding to and preparing for small- and large-scale attacks from adversaries in space, said Doug Loverro, president of Loverro Consulting, which specializes in national security and space guidance. Loverro previously served in leadership positions at both NASA and the Pentagon.
As a result, the requirements for phase 3 will likely address the need to launch multiple smaller satellites into low-Earth orbit at once — such as those deployed by the Space Development Agency, he said.
“You’ll still have large launch vehicles to initially populate constellations, but you’ll have small launch vehicles to go ahead and repair them or replenish them when those satellites on orbit fail,” Loverro said.
Because of the anticipated need for smaller payloads, companies that specialize in smaller rocket launch technology — like Relativity Space, Rocket Lab, Virgin Orbit and Firefly Aerospace — have a chance to compete for future military contracts, he said.
Another trend the industry is seeing is more development of reusable engines with methane fuel over the traditional kerosene used in the RD-180, said Joe Laurienti, founder and CEO of engine/rocket maker Ursa Major. He noted that the ability to reuse a rocket engine not only keeps costs low, but is better for the environment.
“[Methane] burns more cleanly, so if you’re disassembling or inspecting an engine it’s typically a better solution,” he said. “Reusing an engine even once reduces the carbon footprint you’re casting to create those parts, and you’re not dumping the parts in the ocean.”
In June, Ursa Major introduced its own reusable methane-fueled rocket engine called Arroway. The company designed the engine so it can mostly be 3D printed, allowing for it to be scaled during production and easily repaired before being reused, Laurienti said.
Arroway will undergo testing in 2023 and is slated for initial delivery in 2025. Laurienti said Ursa Major will propose its engine as a replacement for the RD-180, as well as a potential upper-stage engine.
Looking forward, Bruno noted that as U.S. adversaries like China continue to field anti-satellite weapons and assert presence in space, “it just puts America in a much better position to have these technologies and an industrial capacity to build the products here on shore.”
ULA will seek to continue with the National Security Space Launch program once Vulcan completes its contracted missions under phase 2, he said.
Overall, the decision to cease use of the RD-180 and have more varied launch vehicles has created a more robust rocket industrial base, Loverro said.
“We see an engine development industry that is far more pervasive across the country into many more shapes and sizes than we saw in the late ‘80s, and the ‘90s and early 2000s,” Loverro added. The lack of development was a combination of the United States’ reliance on the Russian RD-180, a disinterest from the Defense Department in multiple-sized launch vehicles and the absence of a commercial space industry, he noted.
Laurienti said: “The ability to have a sovereign space program is really necessary right now. … The United States could go from a net importer of rocket engines to an exporter, where we’re not just avoiding a security issue … but we’re creating a position of strategic advantage.”